Underreamer.



1. GRANT & L, S. CAMPBELL.

UNDERREAMER,

' APPLICATION FILED AU'G. 30,1915

Patented Apr. 11, 1916.

IIIII B Y I n Ira Mfrs ZAW/rm MJ. CAM/ 5511 rrn starts i s, n

JOHN errant" on FLORENCE, AND LAWRENCE s. CAMPBELL, or Los enemas,

onmronnre.-

UNDERREAMER.

Specification of Letters Patent.

Patented Apr. 1, 916.

Application filed August 30, 1915. Serial No. 48,003. I

To all whom it may concern Be 1t known that we, JOHN GRANT and LAWRENCE S. CAMPBELL, subjects of the King of Great Britain, and residents of Florence and Los Angeles, respectively, in the county of 'Los Angeles and State of California, have invented certain new and useful Improvements in Underreamers, 'of

which the following is a specification.

Our invention is an imp'rovement in underreamers, and the invention has 'for its object to provide a device of the character specified, wherein the reaming mechanism is supported by 'a socket, having interlocking mechanism within the socket, to dispense with openings or projections on the exterior of the socket, and wherein the cutting or striking surface of the bits is firmly locked in extended position, and wherein holding keys, pins and the like are dispensed with;

In the drawings: Figure 1 is a longitudinal section; Fig. 2 is a front view, with the casing removed and with the parts in one position; Fig. 3 is a section on-the line 3-;3

of Fig. 1; Fig. 4 is a bottom planview of Fig. 2, looking at the end of the underreamer; Fig. 5 is a view similar" to Fig. 2 with the parts in another position; Fig. 6 is a perspective view' of one of the bits removed; Fig. 7 is afront view of the-holder detached, and Fig. 8 is a bottom p an view of' Fig. 7

The present embodiment of the invention comprises a body or holder, in the form of a socket 1,'having a stem 2 for connection with asuitable support, and the bits are mounted in the socket. Each of the bits comprises a cutter 3, and a shank 4, each of the cutters being arc-shaped, as shown, and having an inward extension or r1b 5. Each .of these extensions or ribs extends inwardly,

and has one face radial to the cutter, While the other face is formed on a double curve.

' The inner or first mentioned face die at the center of the cutter, and these faces of the extensions of the two members move against each other. 4

The shank' tof each cutter, as shownmore particularly in Fig. 6, has a semi-circular cross section, and the inner or flat faces of the shanks abut, as shown in Fig. 3. Each shank-has a reduced portion 7 at its upperend, and a further 'reduced and .flattened' portion 8 above the portion 7. The inner faces of the shank, and the reduced portions I bits.

7 and 8 are in the same line, forming a planesur'face, and these plane surfaces abut, as shown more particularly in Fig. 3.

Shoulders 9--9 and 10, are formed between the portions 7 and 8, and between the shank'4; and the portion 7 The shoulder 10 is in a plane transverse to the bit, while the shoulder-9+9 consists of two portions, the portion 9 being parallel with a plane through'the shoulder 10, while theportion" 9 inclines upward from the portion 9 The shoulder 10 is adapted to abut against the lower edge of the socket, and the shoulder 99 is adapted to abut against a shoulder 1111 on a sectional holder 12-42 for the The sections 12 and 12 of the holder areheld together by two screws 13 which are passed transversely of the sections at their inwardly extending eye or perforated lug 15 at itsextrerhe lower end. The portion 8 of eachbit has a laterally extending eye 16 near its upper end, and at the inner edge of the bit, and when the bits are in place, the eye 16 of each bit is in alinement with the eye 15 of that section of the holder against which the bit fits. passed through the registering eyes of the bits and sections offthe holder, and a coil spring 18 encircles each rod between. the two eyes. The bits are pivoted together by a .pin 19 which extends through registering diametrical openings in the bits near the upper ends of the shanks, that is, near-the shoulders 10" and justbelow the said shoulders of each bit. I v

Each section 12 and l2 of the holder has a groove or passage20 intermediate its up-v per andlower ends, and extending circumferentially of the holder, from the inner edge thereof-about half the circumference of the curved face of the section, and each groove or passage has a notch 21 in its inner A rod 17 is wall and at its inner end. The socket 1 has inwardly extending lugs22 which are adapted to register withand move in the passages 20, and to engage thenotches 21 to lock the holder and the bits in place in the socket.

It will be evident from the description that the entire connector between the socket and the holder for the bits is within the socket, and there are noopenings, slots, passages or the like, through the socket In order toassemble the under-reainer, the bits are arranged alongside each other, with t surfaces or. walls 6 of the ribs ahutti and. the sections 12"12 of the holder arranged in place, with their lower ends 11 11 against the shoulders S 4) of the respective hits. The pins 17 are inserted, with the coil springs 18 in place.

insertion in the socket.

It all be noticed from an inspection of Figs. Ti. and 8 that the triangular abutting surfaces 1-1 of the sections of the holder do not extend to the periphery of the holder. It will be seen too from an inspection of Fig. 3, that each bit has a lug 23 at its upper end, and this lug 23 of each bit engages the adjacent end of the abutting surface .14 of the adjacent section of the holder.

It will be evident that since the bits are oppositely arranged, that is, since the lug 23 of each bit engages one end of one triangular abutting surface and one end only, the other end being spaced apart from the periphery of the holder provides a passage, extending longitudinally of the holder to the eye 15, and it is through this passage that the lugs 22-of the socket pass during the insertion of the holder and the bits.

In, order to insert the holder and bits they are assembled as above mentioned, and as shown in Fi It will he noticed that the cutter 3 of each bithas an external longitudinally extending lug 24 at its center, and

each of these lugs 2st has its upper end perpendicular to the axis of the hit, as indicated at 25. In inserting the hits, the thumb and fingers of the right hand grasp the bit at these ribs or lugs 24:, and the socket is held in the left hand with the lugs 22 in register with the longitudinal passages between the' sections of the holder and the opposite bits, and the bits and holder are inserted in the socket. The lugs 22 pass down the passages into register with the grooves or passages 20. The bits are now turned to the right, or-the socket to the left,'and the lugs 22 pass along the grooves 20 the inner ends thereof, locking the l'iolder and the bits in place. J

In order to release the hits, the socket is held and downward pressure is made on the surfaces 25.. This controls the springs face 14 and this en a ement orevents col- 'lhe screws 13 are now turned intoplace, and the holder and bits ready for p the working parts.

18, and with the hits held in this position theyv are pushed upward and turned to the left, bringing the lugs 22 again in register with the longitudinal passages of the holder,

be on the holder and the slots 01' grooves in the sockets.

It will be noticed from an inspection of Figs. 1 and 6 that the upper end of the portion 8 of each bit is inclined to fit against the one side of the adjacent triangular surlapsing of the bits, that is, the movement of the cutting surfaces toward each. other. This surface also offers .a brace to prevent inward movement of the bits.

Each of the triangular portions M is isosceles triangle in vertical cross section, and the inclined surfaces of the bitshetween the eyes 16 and the lugs 23 hear against the opposite faces of the triangle.

While a' downward'pressure hf the surfaces will compress the-bits, that is, will move the cutting surfaces toward each other, to permit the withdrawal of the underreamer, yet this compression of the hits does not loosen the bits from the holder. The hits must be turned with respect to the holder, or with respect to the socket before they can he released.

lChe ribs 5 are also cutters, and it is obvious that by extending these ribs beyond the free edges of the cutters 3 a combined boring and under-reaming tool would result.

It will be noticed from an inspection of the drawing that the cutters when inter- 1 locked inside the holder and inserted in the socket completely fill the same at the outer end of the socket, thereby absolutely preventing the entrance of gravel, dirt or foreign matter of any kind to interfere with lnaddition this arrangement makes the reamer practically as strong as though the construction were integral. It will be understood that the pins 22 are merely projections or bosses milled on the inner surface of the socket. it will be also understood that on a full size reamer used in well digging and of sizes as large as eighteen inches in diameter, clampswould be necessary for taking the cutters from the socket and returning them.

The improved construction-is strong, rahle and simple, and easily assembled and disassembled.

"We claim:

1. An under-rea1ner,. comprising a socket, a holder fitting the socket, said holder having a diametrical recess extending from its lower end, and having passages leading to the upper end, a pair oi, bits. each having a 3 end of the socket, a pivotal connection between the'bits below the shoulder, the holder having a lateral groove extending from each side of the recess and in opposite directions, and the socket having inwardly extending pins for engaging the recesses and the grooves to lock the holder in place, each bit having an arc-shaped cutter and a rib extending inwardly from the center of the cutter, said ribs abutting at one face.

2. An under-reamer comprising a socket, a pair of bits, and a holder for the bits, said holder being slotted transversely and diametrically, and the slotted portion extend- .ing tothe upper end of the holder at opposite sides thereof, the .bits having reduced portions fitting within the slots and engaging the upper end of the holder to limit the upward movement of the bits, each bit having a shank semi-circular in cross section and having a shoulder at its upper end for engaging the lower end of the socket, apivotal connection between the bits at the shank and below the socket, a spring arranged between each bit and the holderand normally pressing the bit upward, said holder having oppositely extending peripheral grooves leading from the slot at opposite sides of the holder, and the socket having inwardly extending pins for engaging the slots and grooves to releasably hold the holder and the bits in the socket.

3. An under-reamer, comprising a socket,

a holder for the bits having oppositely arranged longitudinally extending passages leading from its upper end and having circumferentially extending slots leading laterally from the passages, the socket having pins for engaging the slots to lock the holder in place, bits supported by the holder,jand springsarranged between the holder and the bits for extending the bits.

4. An under-reamer, comprising a socket, aholder fitting the socket, said holder having a diametrical recess extending from its lower end, and having passages leadingto the upper end, a pair of bits, each having a shank and fitting within therecess of the holder and bearing against'theholder at its upper end, a spring arranged between each bit and the holder and normally prestting the bit into contact with the holder, and adapted to yield to permit the bits to be mo' -ved 'toward each other to-collapse the same, th'e shank of each bit having a shoulder for engaging the lower end of the socket, a pivotal connection between the bits below the shoulder, the holder having a lateral groove extending from each side of the recess and in opposite directions, and the socket having inwardly extending pins for engaging the recesses and the grooves to lock the holder in place.

5. An under-reamer, comprising a socket having oppositely arranged inwardly extending pins, a holder for the bits fitting the socket andhaving oppositely arranged longitudinally extending passages leading from its upper end for engagement by the pins,

each passage having a laterally extending groove at its lower end for engagement by the pins to lock the holder in the socket.

6. An under-reamer, comprising a holder having a transverse diametrical recess extending to near the upper end and opening the bits fitting the recess and bearing against the upper end, the holder having an inwardly extending perforated lug 'at its lower end for each bit, and each bit having a laterally extending perforated lug at its upper end registering with the adjacent lug of the: holder, a pin in each pair'of registering lugs,

at the upper end at each side of the holder,

tending to near the upper end and opening at the upper end at each side of the holder,

the bits fitting the recess and bearing against the upper end, a socket having inwardly exposite sides of the holder, the holder having a slot extending from each side of therecess for engagement 'by the pins to lock the holder in the socket, and a spring between each bit and holder and. normally pressing the 'bit inwardly. i 8. An under-reamer, comprising a holder having a transverse diametrical. recess extending from near-the upper end and ex-'- .tending at the upper end at opposite sides of the holder, bits having extensions fittingthe recess, each-bit having a lug at its upper end engaging the upper-end of the holder, and a downwardly inclined surface from the lug, the holder being inclined tofitthe inclined surface,- and a spring between each bit and the holder.

9. An under-reamer, comprisinga socket,- a holder fitting the socket and detachably connected with the socket and {having a tending pins for engaging the recess at op- I surface and co: to be conti i o. 11. The combination with a reamer bit holder ing oppositely arranged inclined bear-i; es, reamer bits pivotally connected i mediate their ends and having inclin surfaces bearing against the bearing faces 3o hold. the bits expanded, and springs between the bits and the holder for pressing: the bits toward the bearing surfaces.

R2. The combination with a reamer bit holder having oppositely arranged inclined hearing races, reamer bitspivotally connected intermediate their ends and having inclined surfaces bearing against the bearing .faces to hold the bits expanded, and yielding means arranged between each bit and the holder and pressing the bit toward the adjacent bearing face.

13. In an under-reanier, a blt holder, a pair of bits, each having a spring abutment, the holder having an abutment below the abutment of each bit, and a spring arranged between each pair of abutments and pressing the bits upward, said holder having a wedge-shaped bearing surface fittin b tween the upper ends oi the bits to expand the same.

14. In an under-reamer, a bit holder, a pair of hi each having a spring abutment,- the holder having an abutment below the abutment of each bit, and a spring arranged between each pair of abutments and pressing the bits upward, said holder having means engaging between the upper ends of the bits for expanding the bits w 15. An lIIIClCF-I'QHIIIGI, comprising a socket, a holder for the bits fitting the socket, a r leasable interlocking connection between the holder and the socket and contain within the socket interme mveeea the socket, bits connected with the holder, and a spring arranged between each bit and the holder and normally pressing the bit toward the. holder. 4 v

16. An nndermeamer, comprising a socket, a holder for the bits fitting the socket and an interen gaging pin and bayonet slot connection between the holder and the socket, and contained within the socket.

17. An under-reamer, comprising a socket, a holder fittingthe socket having a diametrical recess and vertical passage from the lower end upwardly forming a ren'iaining c'enter-part in the holder, a pair of bits each having a shank of which the upper end the within the recess and passage in said holder having also an extending end projecting past the remaining center-part in the holder normally engaging with the said center-part adapted to prevent the bits from collapsing. 18. An under-reamer,comprising a socket having a concentric bore, a holder fitting in the bore of said socket having a diametrical recess and passage, a pair of bits each having a shank of semi-circular cross-section fitting slidingly and swingably in the concentric bore of the socket designed to fill said bore in operating position as well as in collapsed position adapted to prevent any waste material from entering the bore in the socket, the upper ends of the shanks being reduced to fit within the recess and passage of the holder engaging with the holder,

and operating means inserted between the bits and the holder within the holder adapted to bring the bits into operating position.

19. An under-reamer,comprising a socket having a concentric bore, a ho l d'er fitting in the bore, a pair of bits each having a shank of semicircular cross-section fitting in the bore of the socket, the bits having cutting edges to the lower ends transversely to the flat sides of the semi-circular shanks projecting outwardly from the center of the device, and operating means engaging the holder with the shanks of the bits within the socket.

JOHN GRANT. LAWRENCE s. CAMPBELL Witnesses M. A. BRODINE, A. 'E. WAGONER. 

